Ultrasonic curved blade

ABSTRACT

An ultrasonic dissection and coagulation system for surgical use is provided. The system includes an ultrasonic instrument, a control module, and a remote actuator. The ultrasonic instrument has a housing and an elongated body portion extending from the housing. An ultrasonic transducer supported within the housing is operatively connected to a cutting jaw by a vibration coupler. The vibration coupler conducts high frequency vibration from the ultrasonic transducer to the cutting jaw. The cutting jaw has a blade surface which is curved downwardly and outwardly in the distal direction with respect to the longitudinal axis of the elongated body portion along its length such that an angle defined by a line drawn tangent to the blade surface and the longitudinal axis of the elongated body portion varies between 5 degrees and 75 degrees. A clamp member having a tissue contact surface is positioned adjacent to the cutting jaw and is movable from an open position in which the tissue contact surface is spaced form the blade surface to a clamped position in which the tissue contact surface is in close juxtaposed alignment with the blade surface to clamp tissue therebetween. The clamp member and the curved cutting jaw combine to enhance contact between tissue and the blade surface of the cutting jaw during cutting. Further, the continuously varying angle of the blade surface with respect to the longitudinal axis of the elongated body portion facilitates selective user control over the application of force on tissue during a cutting or dissecting procedure.

CROSS REFERENCE TO RELATED APPLICATION

[0001] This application is a continuation of U.S. patent applicationSer. No. 09/604,877, filed Jun. 28, 2000, which is a continuation ofSer. No. 09/420,640, filed Oct. 20, 1999, which is a continuation ofSer. No. 08/911,205, filed Aug. 14, 1997, issued U.S. Pat. No.6,024,750, all of which are incorporated herein by reference.

BACKGROUND

[0002] 1. Technical Field

[0003] The present disclosure relates to an ultrasonic dissection andcoagulation system for surgical use. More specifically, the presentdisclosure relates to an ultrasonic instrument including a curved bladeand a clamp member particularly suited for performing dissection andcoagulation of tissue.

[0004] 2. Background of Related Art

[0005] Ultrasonic instruments for surgical use and the benefitsassociated therewith are well known. For example, the use of anultrasonic generator in conjunction with a surgical scalpel facilitatesfaster and easier cutting of organic tissue and accelerates blood vesselclotting in the area of the cut, i.e., accelerated coagulation. Improvedcutting results from increased body tissue to scalpel contact caused bythe high frequency of vibration of the scalpel blade with respect tobody tissue. Improved coagulation results from heat generated by contactbetween the scalpel blade and the body tissue as the scalpel blade isvibrated at a high frequency. Thus, in order to reap the advantagesassociated with ultrasonic energy, good blade to tissue contact isimportant.

[0006] U.S. Pat. No. 3,862,630 (“Balamuth”) discloses an ultrasonicsystem including an ultrasonic motor, a tool member having a workingsurface oriented normal to the direction of mechanical vibrationgenerated by the ultrasonic motor, and a clamp member extending parallelto the tool member for compressing tissue against the tool member. U.S.Pat. No. 5,322,055 (“Davison”) discloses an ultrasonic surgicalinstrument adapted for endoscopic use having a blade and a clamp movablein relation to the blade to capture tissue therebetween. The blade andthe clamp define a clamping region having a plane which is parallel tothe longitudinal axis of the surgical instrument. During an endoscopicprocedure, movement of the instrument is limited to movement along anaxis parallel to the plane of the clamping region. Thus, no additionalblade force is imposed on the body tissue as a result of movement of theinstrument.

[0007] Accordingly, a need exists for an improved ultrasonic surgicalinstrument which is easy to use and provides fast and easy cutting andimproved coagulation.

SUMMARY

[0008] In accordance with the present disclosure, an ultrasonic systemfor dissection and coagulation of tissue is provided. The systemincludes an ultrasonic instrument, a control module, and a remoteactuator. The ultrasonic instrument has a housing and an elongated bodyportion extending from the housing. An ultrasonic transducer supportedwithin the housing is operatively connected to a cutting jaw by avibration coupler. The vibration coupler conducts high frequencyvibration from the ultrasonic transducer to the cutting jaw. The cuttingjaw has a blade surface which is curved outwardly and downwardly alongits surface and thus, curved with respect to the axis of vibration. Thecurved blade surface is preferably configured such that the angledefined between a line tangent to the blade surface and the longitudinalaxis of the elongated body portion varies from about 5 degrees to about45 degrees along the length of the blade surface. A clamp member havinga tissue contact surface is positioned adjacent to the cutting jaw andis movable from an open position in which the tissue contact surface isspaced from the blade surface to a clamped position in which the tissuecontact surface is in close juxtaposed alignment with the blade surfaceto clamp tissue therebetween. The clamp member and the angled bladecombine to enhance contact between tissue and the blade surface of theblade member.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009]FIG. 1 is a perspective view of the ultrasonic dissection andcoagulation system with the ultrasonic instrument inserted partiallythrough a cannula;

[0010]FIG. 2 is a perspective view of the ultrasonic instrument of FIG.1;

[0011]FIG. 3 is a perspective view with parts separated of the clamp ofthe ultrasonic instrument of FIG. 1;

[0012]FIG. 4 is a perspective view with parts separated of the elongatedbody portion of the ultrasonic instrument of FIG. 1;

[0013]FIG. 5 is a perspective view with parts separated of theultrasonic instrument of FIG. 1;

[0014]FIG. 6 is a perspective view with parts separated of the rotationassembly of the ultrasonic instrument of FIG. 1;

[0015]FIG. 7 is a side partial cutaway view of the ultrasonic instrumentof FIG. 1 in the open position;

[0016]FIG. 8 is an enlarged view of the indicated area of detail of FIG.7 illustrating the clamp in the open position;

[0017]FIG. 9 is a perspective view of the distal end of the elongatedbody portion of the ultrasonic instrument of FIG. 1 with the clamp inthe open position;

[0018]FIG. 10 is a perspective partial cutaway view of the distal end ofthe elongated body portion of the ultrasonic instrument of FIG. 1 withthe clamp in the open position;

[0019]FIG. 11 is a front perspective, partial cutaway view of the distalend of the elongated body portion of the ultrasonic instrument of FIG. 1with the clamp in the open position;

[0020]FIG. 12 is a side partial cutaway view of the ultrasonicinstrument of FIG. 1 with the clamp in the clamped (closed) position;

[0021]FIG. 13 is an enlarged view of the indicated area of detail ofFIG. 12 illustrating the clamp in the closed position;

[0022]FIG. 14 is a side cross-sectional view of the distal end of theelongated body portion of the ultrasonic instrument of FIG. 1 in theclamped position;

[0023]FIG. 15 is a perspective view of the ultrasonic instrument of FIG.1 with the elongated body portion partially rotated;

[0024]FIG. 16A is a side view of an alternate embodiment of theultrasonic transducer of FIG. 1;

[0025]FIG. 16B is a side cross-sectional view taken along section line16B-16B of FIG. 16A.

[0026]FIG. 16C is a perspective view with parts separated of theultrasonic transducer of FIG. 16A;

[0027]FIG. 17A is a side view of a torque wrench assembly in engagementwith the ultrasonic transducer of FIG. 16A; and

[0028]FIG. 17B is a side cross-sectional view taken along section line17B-17B of FIG. 17A.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] Preferred embodiments of the presently disclosed ultrasonicdissection and coagulation system will now be described in detail withreference to the drawings, in which like reference numerals designateidentical or corresponding elements in each of the several views.

[0030]FIG. 1 illustrates the ultrasonic dissection and coagulationsystem shown generally as 10. Briefly, dissection and coagulation system10 includes ultrasonic instrument 12, control module 14, and remoteactuator 16. Control module 14 is operatively connected to ultrasonicinstrument 12 by electrically conductive cable 18 and functions tocontrol the power and frequency of current supplied to ultrasonicinstrument 12. Any suitable controller capable of delivering power toultrasonic instrument 12 can be used. Control module 14 does not formpart of the invention and will not be further discussed herein. Remoteactuator 16, e.g., pedal actuator, is operatively connected to controlmodule 14 by electrically conductive cable 20 and can be actuated toinitiate the supply of power to ultrasonic instrument 12 via controlmodule 14 to effect vibratory motion of ultrasonic instrument 12 to cutand coagulate tissue.

[0031] As illustrated in FIG. 2, ultrasonic instrument 12 includeshousing 22 and elongated body portion 24 extending distally therefrom.Housing 22 is preferably formed from molded housing half-sections 22 aand 22 b and includes a barrel portion 26 having a longitudinal axisaligned with the longitudinal axis of body portion 24 and a stationaryhandle portion 28 extending obliquely from barrel portion 26. Ultrasonictransducer 30 is supported within and extends from the proximal end ofhousing 22 and is connected to control module 14 via cable 18. Jawassembly 32 is disposed adjacent the distal end of elongated bodyportion 24 and is actuated by moving movable handle 36 with respect tostationary handle portion 28. Movable handle 36 and stationary handleportion 28 include openings 38 and 40, respectively, to facilitategripping and actuation of ultrasonic instrument 12. Elongated bodyportion 24 is supported within rotatable knob 34 and may be selectivelyrotated by rotating knob 34 with respect to housing 22 to change theorientation of jaw assembly 32.

[0032]FIGS. 3 and 4 illustrate elongated body portion 24 with partsseparated. Elongated body portion 24 includes an outer tube 42 which ispreferably cylindrical and has a proximally located annular flange 44dimensioned to engage rotatable knob 34 (FIG. 2) as described below. Anelongated actuator tube 46, which is also preferably cylindrical, isconfigured to be slidably received within outer tube 42 and includes aproximally located annular flange 48 dimensioned to engage couplingmember 98 (FIG. 5) which is supported within housing 22 (FIG. 2) andwill be described in detail below. Vibration coupler 50 is dimensionedto extend through elongated actuator tube 46 and includes a proximal end52 having a reduced diameter portion 54 configured to operatively engageultrasonic transducer 30 (FIG. 5) and a distal end 56 adapted to beoperatively connected to cutting jaw 58. A plurality of silicon rings 51can be molded or otherwise attached to the nodal points along vibrationcoupler 50 to seal between vibration coupler 50 and actuator tube 46.Preferably, cutting jaw 58 includes an internal proximal threaded bore(not shown) which is dimensioned to receive threaded distal end 56 ofvibration coupler 50. Alternately, cutting jaw 58 can be formedintegrally with vibration coupler 50, cutting jaw 58 may include athreaded proximal end configured to be received within a threaded boreformed in vibration coupler 50, or other attachment devices can be used.A clamp 60 having a clamp body 62 and a tissue contact member 64removably secured to clamp body 62 is operatively connected to thedistal end of actuator tube 46. Clamp body 62 includes a pair of tissuereceiving stops 71 that define the proximal end of the exposed bladesurface 59. Tissue contact member 64 is preferably composed of teflonand is preferably removably fastened to clamp body 62 by a tongue andgroove fastening assembly (reference numerals 61 and 65, respectively),although other fastening assemblies are also envisioned. Tissue contactmember 64 functions to isolate clamp 60, which is preferably metallic,from jaw 58 which is also preferably metallic to prevent metal to metalcontact. Tissue contact member 50 also functions to grip tissue toprevent movement of the tissue with vibrating cutting jaw 58.Alternately, at least one row of teeth may be positioned on clamp 60 togrip tissue, such as disclosed in U.S. patent application Ser. No.08/911,207, which is incorporated herein by reference. Pivot members(pins) 66 located at the proximal end of clamp body 62 are configured tobe received within openings 68 formed in the distal end of outer tube42. A guide slot 70 formed in the distal end of actuator tube 46 permitsrelative movement between actuator tube 46 and clamp body 62 by allowingpins 66 to move in guide slot 70. A pair of camming members 72 are alsoformed on clamp body 62 and are positioned to be received within camslots 74 formed in the distal end of actuator tube 46. Movement ofactuator tube 46 and clamp 60 will be described in detail below.

[0033] Cutting jaw 58 includes a curved blade surface 59 that slopesdownwardly and outwardly in the distal direction. Preferably, the entireblade surface 59 exposed to tissue, i.e., the portion of blade surface59 between tissue receiving stops 71 and the distal end of blade surface59, has a tangent which defines an angle with respect to thelongitudinal axis of elongated body portion 24 that varies along thelength of blade surface 59 from about 5 degrees to about 75 degrees.Ideally, the angle defined by a line tangent to the blade surface andthe longitudinal axis of elongated body portion 24 varies from about 5degrees to about 45 degrees along the length of the blade surface. Thecurved blade surface provides better visibility at the surgical site.Clamp 60 is movable from an open position in which tissue contact member64 is spaced apart from blade surface 59 (FIGS. 7 and 8) to a clampedposition in which tissue contact member is in juxtaposed close alignmentwith blade surface 59 (FIGS. 11-13) to clamp tissue therebetween. Theinterior surface of tissue contact member 64 is curved to correspond toblade surface 59. In the clamped position, note the positioning oftissue contact member 64 with respect to blade surface 59. Actuation ofclamp 60 from the open position to the clamped position will bedescribed in detail below.

[0034] Referring now to FIGS. 5 and 6, the handle assembly and therotation assembly will now be discussed. Housing half-sections 22 a and22 b define a chamber 76 configured to receive a portion of ultrasonictransducer 30. Chamber 76 has an opening 78 communicating with theinterior of housing 22. Ultrasonic transducer 30 includes a bore 80configured to receive proximal end 54 of vibration coupler 50. In theassembled condition, proximal end 54 extends through opening 78 intobore 80. Ultrasonic transducer 30 may be secured within housing 22 tovibration coupler 50 using any known attachment apparatus. Preferably, atorque wrench, such as disclosed in copending U.S. patent applicationSer. No. 08/911,207, now U.S. Pat. No. 6,036,667, incorporated herein byreference above, can be used to secure ultrasonic transducer 30 tovibration coupler 50. As disclosed therein, the proximal end oftransducer 30 may be configured to engage the torque wrench. Movablehandle 36 is pivotally connected between housing half-sections 22 a and22 b about pivot pin 82 which extends through holes 84 formed in legs 86of movable handle 36. A cam slot 88 formed in each leg 86 is configuredto receive a protrusion 90 projecting outwardly from coupling member 98(FIG. 6).

[0035] As illustrated in FIG. 6, coupling member 98 operatively connectsmovable handle 36 to actuator tube 46 and is preferably formed frommolded half-sections 98 a and 98 b to define a throughbore 100dimensioned to slidably receive the proximal end of vibration coupler50. Coupling member 98 has an inner distally located annular groove 102dimensioned to receive annular flange 48 of actuator tube 46 and anouter proximally located annular groove 104. Groove 104 is positioned toreceive an annular rib 106 formed on the internal wall of a swivelmember 108 (FIG. 5). Swivel member 108 is preferably formed from moldedhalf-sections 108 a and 108 b and permits rotation of coupling member 98relative to movable handle 36. Protrusions 90 project outwardly fromsidewalls of swivel member 108 and extend through cam slots 88 ofmovable handle 36 (FIG. 5).

[0036] Referring to FIGS. 5 and 6, rotation knob 34 is preferably formedfrom molded half-sections 34 a and 34 b and includes a proximal cavity110 for slidably supporting coupling member 98 and a distal bore 112dimensioned to receive outer tube 42. An annular groove 114 formed inbore 112 is positioned to receive annular flange 44 of outer tube 42.The outer wall of knob 34 has a proximally located annular ring 116dimensioned to be rotatably received within annular slot 118 formed inopening 120 of housing 22. The outer wall of knob 34 also includesscalloped surface 122 to facilitate gripping of rotatable knob 34.Annular ring 116 permits rotation of knob 34 with respect to housing 22while preventing axial movement with respect thereto. A pair ofcylindrical rods 124 extend between half-sections 34 a and 34 b througha rectangular opening 126 formed in coupling member 98. Rods 124 engagea pair of concave recesses 128 formed in fitting 130 which is fastenedabout vibration coupler 50, such that rotation of knob 34 causesrotation of vibration coupler 50 and thus rotation of blade 58 and clamp60. Alternately, recesses 128 can be monolithically formed withvibration coupler 50.

[0037] FIGS. 7-10 illustrate ultrasonic instrument 12 with clamp 60 inthe open position. The elongated body 24 which includes clamp 60 andblade 58, and housing 22 which includes handles 28 and 36, are packagedas an integral unit, e.g., non-detachably connected, that requires noassembly by the user prior to use. That is, the user needs only toattach transducer 30 to housing 22 to ready instrument 12 for use. Inthe open position, movable handle 36 is spaced rearwardly fromstationary handle portion 28 and protrusions 90 are positioned in thelower proximal portion of cam slots 88. At the distal end of ultrasonicinstrument 12, pivot members 66 are positioned near the distal end ofguide slots 70 and camming members 72 are positioned in the upper distalportion of cam slots 74. Tissue contact member 64 of clamp 60 is spacedfrom blade surface 59 to define a tissue receiving area 132. Theproximal end of tissue receiving area 132 is defined by tissue receivingstops 71 which are preferably integrally formed with clamp body 62 andextend below blade surface 59. Preferably, the distal end of blade 58 isrounded to prevent inadvertent damage to tissue during use of instrument12 and tissue contact surface 64 is also preferably formed with alongitudinally extending concavity 67 to receive tissue therein.Alternately, the distal end of blade 58 may be formed in any shape whichmay be suitable to a particular surgical application, i.e., pointed,flat, etc. Moreover, tissue contact surface 64 need not be formed with aconcavity but may be flat, angled, etc.

[0038] Referring to FIGS. 11-15, when movable handle 36 is pivotedclockwise about pivot member 82 towards stationary handle portion 28, inthe direction indicated by arrow “A” in FIG. 11, cam slot 88 engagesprotrusion 90 of swivel member 108 to advance coupling member 98distally within cavity 110 of rotation knob 34. Since actuator tube 46is attached to coupling member 98 by an annular flange 48, actuator tube46 is also advanced distally in the direction indicated by arrow “B” inFIG. 12. Movement of actuator tube 46 distally causes cam slots 74 tomove into engagement with camming members 72 to pivot clamp body 62about pivot members 66, in the direction indicated by arrow “C” in FIG.13, to move clamp member 62 and tissue contact member 64 into theclamped position. In the clamped position, protrusions 90 are located ina central portion of cam slots 88, pivot members 66 are located near theproximal end of guide slots 70, and camming members 72 are located inthe proximal lower portion of cam slots 74.

[0039] Elongated body portion 24 can be freely rotated with respect tohousing 22 by rotating rotation knob 34. As illustrated in FIG. 15,rotation of knob 34 in the direction indicated by arrow “D” causesrotation of jaw assembly 32 in the direction indicated by arrow “E”.Knob 34 is positioned adjacent housing 22 to facilitate one handedoperation of both movable handle 36 and rotation knob 34.

[0040] Referring again to FIG. 1, elongated body portion 24 isdimensioned to extend through a trocar assembly 140, and is preferablydimensioned to extend through a 5 mm trocar assembly. During use,elongated body portion 24 is slid through trocar assembly 140 with jawassembly 32 in the clamped or closed position to a position adjacenttissue (not shown) to be dissected and/or coagulated. An optical unit(not shown) can also be positioned adjacent the surgical site tofacilitate viewing of the procedure. Jaw assembly 32 is opened andtissue to be dissected and/or coagulated is positioned within tissuereceiving area 132 (See also FIG. 9). Tissue receiving stops 71 preventtissue from moving past the proximal end of blade surface 59. Next, jawassembly 32 is closed to clamp tissue between tissue contact member 64and blade surface 59. Power is supplied to ultrasonic instrument 12 viacontrol module 14 to initiate vibration of blade 58 to effect dissectionand/or coagulation of tissue. Because of the curve of blade surface 59,the force applied by blade surface 59 to the tissue being dissected canbe selectively increased or decreased as instrument 12 is moved forwardthrough trocar assembly 140 by adjusting the location of the tissue onblade surface 59 and thus changing the angle of the force applied to thetissue being dissected.

[0041] FIGS. 16A-16C illustrate an alternate embodiment of theultrasonic transducer shown generally as 230. Ultrasonic transducer 230includes a housing 231 having a proximal housing portion 232 and adistal housing portion 234. Proximal housing portion 232 has a scallopedsection 236 adjacent its proximal end. Transducer horn 238 is supportedwithin housing 231 by support collar 240 and annular ring 242. Thedistal end of transducer horn 238 includes a threaded bore 244dimensioned to engage reduced diameter portion 54 of vibration coupler50 (FIG. 4). As best illustrated in FIG. 16B, transducer horn 238 isformed with annular flange 246, about which annular ring 242 isreceived. The proximal end of support collar 240 also includes anannular flange 248 which, in an assembled condition, is clamped betweenproximal and distal housing portions 232 and 234 to fixedly retainsupport collar 240 in position within housing 231. The distal end ofsupport collar 240 engages annular ring 242 to retain annular ring 242and thus horn 238 in a longitudinally fixed position within housing 231.

[0042] Referring to FIGS. 17A-17B, torque wrench assembly 250 isconfigured and dimensioned to engage scalloped section 236 of ultrasonictransducer 230 to facilitate assembly of transducer assembly 230 withthe remaining portion of ultrasonic instrument 12. Torque wrenchassembly 250 assures that horn 238 and vibration coupler 50 (FIG. 4) areproperly connected, i.e., properly torqued.

[0043] It will be understood that various modifications may be made tothe embodiments herein. For example, vibration coupler 50 and blade 58may be monolithically formed or attached using structure other thanscrew threads. Different actuator assemblies other than the actuatortube having a camming surface can be used to pivot the clamp member tothe clamped position. Further, the elongated body portion of theinstrument can be dimensioned to extend through other than 5mm trocarassemblies, e.g., 10 mm, 12 mm, etc. Therefore, the above descriptionshould not be construed as limiting, but merely as exemplifications ofpreferred embodiments. Those skilled in the art will envision othermodifications within the scope and spirit of the claims appended hereto.

What is claimed is:
 1. An ultrasonic instrument comprising: a) avibration coupler; b) a cutting jaw operatively connected to thevibration coupler; c) a clamp member supported adjacent to the cuttingjaw, the clamp member being moveable in relation to the cutting jawbetween an open position in which at least a portion of the clamp memberis spaced from the cutting jaw and a closed position in which the clampmember and the cutting jaw are in substantially juxtaposed alignment;and d) a rotatable member operatively associated with the vibrationcoupler, the clamp member and the cutting jaw, the rotatable memberbeing rotatable to cause corresponding rotation of the clamp member andcutting jaw about a longitudinal axis of the instrument.
 2. Anultrasonic instrument according to claim 1, wherein the cutting jawincludes a curved cutting surface.
 3. An ultrasonic instrument accordingto claim 2, wherein the curved cutting surface is convex.
 4. Anultrasonic instrument according to claim 1, wherein the clamp memberincludes a tissue contact surface removably fastened to the clampmember.
 5. An ultrasonic instrument according to claim 1, furtherincluding a handle assembly, the vibration coupler extending distallyfrom the handle assembly, the handle assembly including a moveablehandle operatively connected to the clamp member and being moveable tomove the clamp member between the open and closed positions.
 6. Anultrasonic instrument according to claim 1, wherein the clamp memberincludes a pair of tissue engaging stops.
 7. An ultrasonic instrumentcomprising: a) a handle assembly; b) a vibration coupler supported byand extending distally from the handle assembly; c) a cutting jaw havinga cutting surface operatively connected to the vibration coupler; d) aclamp member supported adjacent to the cutting jaw, the clamp member andthe cutting jaw defining a tissue receiving area, the clamp member beingmoveable between open and closed positions in relation to the cuttingjaw and having a tissue engaging stop positioned to engage tissue andprevent positioning of tissue beyond the proximal end of the cuttingsurface of the cutting jaw. 8) An ultrasonic instrument according toclaim 7, further including an actuator tube slidably positioned aboutthe vibration coupler, a distal end of the actuator tube including a camslot configured to receive cam members formed on the clamp member, theactuator tube being moveable between advanced and retracted positionsabout the vibration coupler in response to actuation of the handleassembly to effect movement of the clamp member between the open andclosed positions. 9) An ultrasonic instrument according to claim 8,wherein the handle assembly includes a stationary handle and a moveablehandle, the moveable handle being operably connected to a proximal endof the actuator tube. 10) An ultrasonic instrument according to claim 9,further including a coupling member, the coupling member interconnectingthe actuator tube and the moveable handle. 11) An ultrasonic instrumentaccording to claim 10, wherein the coupling member includes a swivelmember, the swivel member being positioned to permit rotation of thecoupling member in relation to the moveable handle. 12) An ultrasonicinstrument according to claim 11, wherein the coupling member isoperably connected to a rotatable knob positioned adjacent the handleassembly, the rotatable knob being rotatably secured to the handleassembly such that rotation of the rotatable knob in relation to thehandle assembly effects corresponding rotation of the coupling memberand the clamp member. 13) An ultrasonic instrument according to claim12, wherein the vibration coupler is rotatably fixed to the rotatableknob such that rotation of the rotatable knob also effects correspondingrotation of the vibration coupler and the cutting jaw. 14) An ultrasonicinstrument according to claim 8, further including an outer tubepositioned about the actuator tube, the clamp member being pivotallyconnected to the outer tube. 15) An ultrasonic instrument according toclaim 7, wherein the cutting surface of the cutting jaw is curved alongthe longitudinal axis of the instrument. 16) An ultrasonic instrumentaccording to claim 15, wherein the curved cutting surface is convex. 17)An ultrasonic instrument according to claim 7, wherein the clamp memberincludes a tissue contact surface removably fastened to the clampmember. 18) An ultrasonic instrument according to claim 13, wherein thecutting surface of the cutting jaw is convex along the longitudinal axisof the instrument. 19) An ultrasonic instrument according to claim 7,wherein a transverse cross-section of the clamp member defines aconcavity. 20) An ultrasonic instrument according to claim 19, wherein atransverse cross-section of the cutting jaw defines a triangular shapehaving an apex, wherein the apex of the triangular shape is the cuttingsurface.